Category: Water & Minerals

The 14 Essential Minerals

Plants require a mix of both macronutrients and micronutrients to thrive. Here’s a breakdown:

1. Macronutrients:
   • Primary: Nitrogen (N), Phosphorus (P), and Potassium (K). Often referred to as N-P-K, these are the three main nutrients you’ll see listed on most fertilizer labels.
   • Secondary: Calcium (Ca), Magnesium (Mg), and Sulfur (S).
2. Micronutrients:
   • Iron (Fe), Boron (B), Chlorine (Cl), Manganese (Mn), Zinc (Zn), Copper (Cu), Molybdenum (Mo), and Nickel (Ni).

Understanding Fertilizer Labels:

When choosing a hydroponic fertilizer, it’s crucial to understand the label. A label might read “10-20-10”, which represents the N-P-K ratio. This means:

• 10% Nitrogen
• 20% Phosphorus
• 10% Potassium

The remaining 60% consists of other nutrients and filler material.

Monitoring and Adjusting:

It’s essential to monitor the nutrient solution’s pH and electrical conductivity (EC) regularly. The pH level affects nutrient absorption, while EC measures the solution’s salt concentration, indicating nutrient strength.

• pH Levels: Most hydroponic plants prefer a pH range of 5.5 to 6.5. Outside this range, certain nutrients become less available, leading to deficiencies.
• EC Levels: If the EC is too high, it indicates an excess of nutrients, which can lead to nutrient burn. If it’s too low, your plants may not be getting enough nutrients.

Water Quality:

The quality of the water used in hydroponics plays a significant role. Hard water or water with high mineral content can interfere with nutrient absorption. Using reverse osmosis water or rainwater can help ensure a purer starting point for your nutrient solution.

Understanding Calcium and Magnesium in Hydroponic Systems

In hydroponic systems, calcium and magnesium play a crucial role. However, they’re often packaged separately from other essential minerals in fertilizers. Here’s why:

Why Separate Calcium and Magnesium?
When calcium is mixed with water alongside phosphorus and sulfur, they can combine and create insoluble clumps. This makes the nutrients unavailable to plants. To prevent this, calcium and magnesium should be dissolved in water separately before being combined with other fertilizers.

Adjusting Dosages Based on Your Water Source:
The amount of calcium and magnesium you need to add depends on your water’s initial mineral content:

• Tap Water: Typically contains native calcium and magnesium. On average, tap water has a mineral content of 0.15 EC (150 TDS). However, this can vary based on your location. Before adding any fertilizers, check your local water report or use testing strips or an EC meter to determine its mineral content.
• Rain or R/O Water: Lacks significant amounts of calcium and magnesium. R/O (Reverse Osmosis) water has had most of its minerals removed, making it almost “pure” water. For such water sources, you’ll need to add more calcium and magnesium to reach an ideal starting point of approximately 0.3 EC (300 TDS).

Mastering Mineral Measurements: The Role of EC Meters in Hydroponics

In the world of hydroponics, precision is paramount. Ensuring your plants receive the right amount of nutrients is a delicate balancing act, and the key to this balance lies in understanding and measuring the volume of minerals in your feeding solution.

What is EC and Why is it Important?
EC, or Electrical Conductivity, is a measure of the dissolved solids in your water, primarily the minerals from fertilizers. It provides a snapshot of the nutrient density in your feeding solution, ensuring your plants aren’t underfed or overfed.

How Does an EC Meter Work?
An EC meter gauges the resistance to an electrical charge between two submerged filaments. The presence of dissolved solids in the water affects this resistance, allowing the meter to estimate the volume of these solids.

The Role of Light and Plant Varieties
Environmental factors, especially light, can influence how plants consume nutrients. Different strains might also have varied nutritional needs. Regularly monitoring your feeding solution with an EC meter helps in adjusting the fertilizer dosage to cater to these unique requirements.

TDS and PPM: Other Measurement Standards
While EC is a widely accepted standard, some meters display their readings as TDS (Total Dissolved Solids) or PPM (Parts Per Million). Think of these as different units, much like inches and centimeters. However, it’s crucial to note that PPM can be inconsistent, sometimes equating to 500 EC or 700 EC. For clarity and consistency, it’s advisable to stick with EC or TDS.

Simple Conversion Guide:

• 1 EC = 500 TDS

In Conclusion
Mastering the art of hydroponics requires a keen understanding of your plants’ nutritional needs. An EC meter is an invaluable tool in this journey, ensuring your plants thrive in a perfectly balanced environment.

Water can be either neutral, acidic or basic.

The pH scale is the measurement of how acidic or basic water is, ranging from 0 to 14. 7 is neutral—neither acidic nor basic. A number lower than 7 is acidic. A number higher than 7 is basic.

The pH of water changes when acidic or basic substances are added to it. For example, adding minerals changes the pH of water because minerals have acidic and basic properties. Some substances are more acidic or basic than others and will have a greater influence on the pH of your water than others.

Accurate measurement of pH is important because the pH of water affects a plant’s ability to absorb minerals efficiently. When pH is out of range in the irrigation water a plant can even become blocked from absorbing nutrients that they need to survive.

pH also has an effect on the solubility of minerals. Minerals are soluble when water has a pH of 5.6-6.4. If pH drifts out of this range, minerals can precipitate out of solution. For example, calcium, iron and phosphate start to leave solution when pH rises above 6.5.

The pH of a feeding solution for cannabis plants should be kept between 5.8-6.3. This range optimizes mineral solubility and uptake.

The pH of water is measured using an electronic pH meter. pH meters must be calibrated before use using calibration solutions.

Growers adjust the pH of their solutions with commercially available pH Up and pH Down solutions. pH Up is a concentrated base that raises pH. pH Down is a concentrated acid that lowers pH.

pH up and down solutions are very concentrated and are best administered to water with a syringe or dropper.

pH needs to be monitored regularly throughout the entire growing process and adjusted to keep it within recommended range.

Rain, tap or well water always comes pre-loaded with some native substances before fertilizer gets added to it. When water has more substances than average it’s called hard water. When water has less substances than average it’s called soft water.

The predominant minerals found natively in tap water are calcium and magnesium.

A measurement of your water taken before nutrients are added will determine its hardness:

Very Soft Water – rain water and R/O water.
0-70 TDS
0 – 0.14 EC

Soft Water – average tap water.
70-140 TDS
0.14 – 0.28 EC

Slightly Hard Water – average tap water.
140-210 TDS
0.28 – 0.42 EC

Moderately Hard Water
210-320 TDS
0.42 – 0.64 EC

Hard Water – Very difficult to work with.
320-530 TDS
0.64 – 1.06 EC

R/O or rain water is Very Soft, close to 0 EC (0 TDS). Tap water is often around 0.1 EC (150 TDS), but this depends on municipality. Use Cal-Mag to raise the mineral content of your water. An EC metre can tell you when you’ve added enough Cal-Mag to your irrigation water to reach a target dosage of 0.3 EC (300 TDS).

Excessively hard water is very difficult to work with because adding fertilizers to water that is already crowded with minerals creates a toxic solution. To fix hard water use a reverse osmosis process to take minerals out, then put fertilizer in.

After treating water with a reverse osmosis machine, add calcium and magnesium back to it at a 2:1 ratio,  raising its mineral content to 0.3 EC (300 TDS). 

When nutrients are added to water the resulting mixture is called a feeding solution.

There are maximum limits for how many minerals should be in a feeding solution for each stage of plant growth. When nutrients are present at healthy levels, plants are able to uptake and use them effectively. When there’s an excess of minerals, a build up accumulates in the growing media which can cause several serious problems:

• Mineral buildup can cause plants to stop taking up water.

• Minerals trapped in the growing media bind with minerals in the feeding solution, blocking plants from absorbing the bound minerals. This leads to a nutrient deficiency of the minerals that are bound.

• Mineral buildup in the grow media causes pH to swing in the roots zone. Irregular pH causes minerals to precipitate out of solution and prevents plants from absorbing minerals.

Mineral buildups occur when plants are fed more minerals than they can absorb and they should be avoided. 

The total amount of minerals that should be in a feeding solution depends on plant’s stage of growth. Young seedlings and clones use fewer minerals. As plants get older and larger they use more minerals, until they reach late bloom when they start to consume less.

The list below details the total approximate recommended mineral concentration after all nutrients and additives have been added to water for all the growth stages of cannabis. Maintaining a feeding solution within these ranges helps prevent over fertilization problems.

Clone & Seedling:
350 – 500 TDS
0.7 – 1 EC

Early Vegetative:
600 – 700 TDS
1.2 – 1.4 EC

Late Vegetative:
700 – 800 TDS
1.4 – 1.6 EC

Early Flowering:
900 – 1100 TDS
1.8 – 2.2 EC

Middle Flowering:
1000 – 1200 TDS
2 – 2.4 EC

Late Flowering:
900 – 1100 TDS
1.8 – 2.2 EC

Water sourced from the tap can contain too much chlorine. Chlorine gets added at the municipal reservoir to kill microorganisms and bacteria to make drinking water more safe for humans. For plants, high levels of chlorine are harmful to their root zone and therefore should be removed. Before adding any fertilizers, remove chlorine from your tap water using a chlorine filter. Vitamin C (ascorbic acid) tablets will also get rid of chlorine.

Fertilized irrigation water can attract fungi infections that consume nutrients. This is bad because fungi destroys fertilizer so plants can’t use it. Prevent fungi colonies from developing by adding sodium benzonate to the irrigation water at a concentration of .13 gram / 100 litres.

Powdered fertilizers must be dissolved with water before use. Dissolve powders thoroughly in a small volume of water, then pour the resulting solution into a larger volume of water. Heating water helps powders dissolve better. Calcium and magnesium powdered fertilizer needs to dissolved with water independently of other fertilizers because it can cause clumping when mixed at same time with phosphorus and sulphur. Always use a mask when working with fertilizers to avoid inhalation. 

Plant stimulants aid in how plants process minerals. They help plants access and take up water and minerals more effectively. Bio-stimulants make plants more productive and stress resistant, improving growth results beyond what can be achieved with mineral fertilizers alone.

Examples of some different types of plant stimulants:

• Humic Acid and Amino Acid are chelators. Chelators help plants take up minerals better. 

• Kelp extract contains growth hormones that are beneficial for stimulating plant growth processes.

• Yucca is a speading agent that helps feeding solution spread out better on the leaf surface and in grow media, improving nutrient absorption by plants. 

Bio-stimulants are not fertilizer. They enhance the effectiveness of fertilizer. They are not required for plant life but will help you optimize your garden for best results.

Roots are not the only way plants can absorb nutrients. Plants are also able to absorb nutrients through their leaves. Foliar sprays are feeding solutions that are sprayed on a plants leaves.

Foliar sprays can help clones root faster. Cuttings taken from a mother plant to make clones have no roots and no other way to absorb water & nutrients except through their foliage. During their rooting period, clones are kept on life support in a humidity dome where they survive only by absorbing water & nutrients through their foliage from the air. Support vulnerable clones with foliar feeding directly on their leaves. Apply a foliar spray containing Kelp Extract and Humic Acid to clones because it will speed up their root development and boost their survival rate.

Foliar sprays are also very effective for emergency first-aid correction of nutrient deficiencies. Plants can absorb nutrients sprayed directly on their leaves more immediately than absorption through their roots. If your plants have a nutrient deficiency, apply a foliar spray in addition to correcting their feeding solution because foliar absorption offers the advantage of speed. A faster delivery of deficient minerals reduces stress and damage and can in more extreme cases make the difference between life and death for your plants.

A foliar spray is improved with the addition of yucca extract. Yucca is a water spreading agent that makes water spread out and cover a leaf’s surface rather than beading up, allowing nutrients to be more thoroughly distributed and absorbed. Add some yucca to your Foliar sprays to make them work better.

Foliar sprays should not be applied under strong lighting because water can act as a lens that can burn foliage. Apply foliar sprays only when lights are off.

Not all products should be used as a foliar spray, and some products should only be applied as a foliar spray during the vegetative growth phase. Before using a product in a foliar spray check if it is indicated for foliar use and which stages of growth it can be used.